Furans are compounds that are inevitably formed after the pretreatment of lignocellulosic biomass (the first step in the production of "cellulose ethanol"). Pretreatment (using chemical or thermochemical treatments) breaks the lignin wrapping around the plant biomass, and breaks down the cellulose into simple sugars for ethanol fermentation. When formed in large amounts (after biomass pretreatment), furans (or furan derivatives like furural and hydroxymethylfufural (HMF)) can inhibit ethanol-fermenting microorganisms, and lower ethanol fermentation efficiency. Researchers from the Delft University of Technology (TU Delft, the Netherlands) report the discovery of a bacterium which can degrade furan into harmless components, but leaves the sugars in the pretreated biomass intact. This represents a major breakthrough toward lowering production cost and increasing cellulose-ethanol production performance. The TU Delft researchers were able to isolate a Gram-negative soil microorganism, Cupriavidus basilensis HMF14, which can metabolize furfural and hydroxymethylfurural (both furan derivatives). They analyzed the genes of the degradation process, and successfully expressed them in a heterologous host, Pseudomonas putida S12. The use of furan degrading microorganisms during pretreatment, bypasses the detoxification step and can improve microbial utilization of sugars by ethanol-fermenting microorganisms. The full report is published in the Proceedings of the National Academy of Sciences (URL above)..